Dry summers, cold winters singe some area evergreens

Unfortunately, things might get worse before they get better for some area trees suffering from winter burn.

In winter, a sunny day may cause a tree to open its pores, which allows moisture to escape. Cycles of warm and cold weather are especially damaging. Winds dry out the tree tips even further, causing winter injury.
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Two dry summers followed by a cold, windy winter have singed some evergreens, resulting in widespread cases of winter burn. But unless a tree is entirely rust-colored, property owners may have to wait a bit to determine the extent of damage.

Rust-tipped trees may send out a new round of buds. Val Cervenka, a Minnesota Department of Natural Resources forest health program coordinator based in St. Paul, suggests scraping needles at boughs’ end. If you see green, the tree is still growing.

Eventually, dead needles will drop, leaving a gap.

“This is kind of what happens in nature. We can’t protect trees like furniture,” Cervenka said. “Don’t give up hope that that tree’s going to survive. It will survive. It will maybe just look unsightly for the year or for the season.”

Beth Berlin, a University of Minnesota Extension horticulture educator based in Stearns County, said winter burn can get worse in the spring before it gets better if moisture doesn’t reach tree roots. She suggests waiting for a couple of months to see if new buds emerge.

Trees growing in yards may be more susceptible because they have less wind protection. Winter sun may exacerbate drying.

In winter, Cervenka said a sunny day may cause a tree to open its pores, which allows moisture to escape. Cycles of warm and cold weather are especially damaging. Winds dry out the tree tips even further, causing winter injury.

Trees growing in sandy soil are particularly susceptible.

For property owners with a few evergreens, safeguarding may start with watering — about 1 inch per week — up until the first fall frost, and again in the spring once the frost is out.

For now, Cervenka said nothing much can be done.

“Absolutely don’t panic and don’t start cutting off tips,” Cervenka said. Pruning leaves a wound that opens the tree up to more disease and drying. “It’s a closed system until you wound the tree and then you’re letting everybody in.”

But for property owners more concerned about aesthetics, Berlin said the best time to prune is in midsummer after new growth appears.